Unless you have a whole load of FD lenses already forget trying them. FD is one of the few mounts that it is not easy to convert to the EF mount. That is because they use the same 43mm IIRC registration distance from the lens mount face to the sensor. This means that the converter has to move the lens forwards, which means the lens will no longer focus to infinity. You would need a converter with a lens element to allow infinity focus. Canon did make a good one for a while, but they are expensive and hard to find on the secondhand market. There are though a whole range of other system mounts that will easily convert, since Canon use about the shortest registration distance of any 35mm SLR system. Those other systems lenses need to be mounted further out anyway, making fitting the adaptor much simpler with no lens needed. Probably the two most commonly used mounts are the old M42 found on a whole raft of lenses, from many old Eastern Bloc countries, as well as Pentax and Takumar lenses from Japan. Although Pentax K bayonet mount lenses will adapt, the stop down lever can cause issues when adapting. The other common mount that is used is the Nikon F, yes Nikon glass adapts better to Canon EOS than Canon FD! Contax/Yashica (CY) lenses also adapt well to EOS, many of the Contax branded lenses were actually made in Japan by Yashica, not Germany so the quality is pretty good.
Alan
